1. Field of the Invention
The invention generally relates to an optical component and a light source module, and more particularly, to a light guide plate (LGP) and a backlight module.
2. Description of Related Art
Along with the flourishing developments of flat panel display (FPD) technology, liquid crystal displays (LCDs) have played a major role in the mainstream display market and are widely used in people's daily lives to replace the traditional cathode ray tube (CRT) display. Since an LCD panel may not be self-luminescent, a backlight module is employed to provide a backlight source. According to the disposing position of the light-emitting devices in a backlight module, the backlight module is categorized into a direct type backlight module and a side type backlight module, wherein the side type backlight module is able to guide light from a side to the front thereof to form a surface light source by employing an LGP serving as the critical component.
In a side type backlight module where light emitting diodes (LEDs) are used as the light-emitting devices, a plurality of LEDs are arranged beside the light incident surface of the LGP. The light beams emitted from the LEDs have directionality, i.e., the divergent angle thereof is limited and certain. As a result, when the light beams from the LEDs enter the LGP through the light incident surface, dim regions with a luminance lower than other areas and bright regions with a luminance higher than other areas are formed. The above-mentioned bright regions are usually termed as hot spots.
The dim regions and the bright regions may be observed by naked-eyes, so that the LCD frames have a lower display quality. In addition, the phenomena of dim regions and bright regions degrade the overall uniformity of the surface light source provided by the backlight module and thereby degrade the overall optical quality of the LCD.